Some time ago I won Ryzen 3700x in a Fnatic contest, which was partnered with AMD.
I am wondering how can I claim a warranty in case if something happens with CPU. Since I didn't buy it, I don't have any proof of purchase. All I have is an email with information that I won the CPU.
This type of situation came up a while back where another User won a CPU from a AMD contest.
Seems like AMD Warranty is voided on AMD Giveaways of hardware.
I would contact the company that ran the promotion where you won the CPU and asked them about the Warranty issue on your CPU.